Page 101 - Predicting survival in patients with spinal bone metastasesL

INTRODUCTION
Spinal bone metastases (SBM) develop in up to 70% of cancer patients1. Back pain and neurological deficit are the most frequently reported symptoms2-4. Current management of SBM focuses on optimizing a patient’s quality of life by providing effective pain relief and preserving or restoring neurological function2. In addition, spinal instability is a third indication for treatment, as it can lead to the aforementioned symptoms. Whereas patients with stable spines can be treated using non-invasive procedures such as radiotherapy, patients with unstable spines potentially require surgical fixation, either through minimally invasive techniques such as percutaneous stabilization or through more invasive procedures involving open fixation.
Assessment of spinal stability is challenging and is mostly done by relying on clinical experience, in the absence of validated guidelines or an established predetermined set of risk factors. The absence of a standardized approach hinders communication between physicians of different medical specialties and can result in under- as well as overdiagnosis of spinal instability.
In 2010, the Spinal Oncology Study Group introduced the Spinal Instability Neoplastic Score (SINS); the first consensus-based guideline that aids in the assessment of a patient’s risk of spinal instability in the setting of neoplastic spinal disease5. The SINS determines tumor-related instability based on six criteria and classifies the spinal column as stable, potentially unstable or unstable. Surgical consultation is recommended for patients with a spinal column classified as either potentially unstable or unstable. As such, the SINS facilitates interdisciplinary communication, assesses and categorizes spinal instability and optimizes treatment decision making.
Previous studies have already shown that the SINS has a substantial to excellent inter-observer and intra-observer reliability6-9. Nevertheless, for it to be useful in clinical practice, it should also be evaluated whether the score is indeed predictive of progressive spinal instability when applied to longitudinal patient cohorts. Studies have shown that the total SINS score is not predictive for new or progressive vertebral compression fractures (VCF) in patients receiving high dose
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